We recently reported some new photocyclizations of a-(0-toly1) acetophenones which were concluded to involve 1, 5-biradical intermediates. 2 We have studied these biradicals by laser flash spectroscopy and have observed that additional products resulting from excitation of the biradicals are formed under intense laser irradiation. Although there are several examples of the photochemistry of cryogenically isolated biradi~ als,~ ...
